Collet



H. D. FOWLIE Oct. 30, 1951 COLLET Filed June 28, 1946 Em Q MN wmwwmm H UHL ANN E m. R m F m0 A Patented Oct. 30, 1951 I i UNITED STATES PATENT OFFICE COLLET Henry D. Fowlie, Royal Oak, Mich. Application June 28, 1946, Serial No. 680,237

2 Claims.

The present invention relates to collet construction for use in pencils, tool holders, or the like, and specifically to collets for gripping small shanks of tools or pencil leads.

Among the objects of the invention is a collet which closes upon the object to be held, with the griping surfaces parallel to the surfaces to be griped even if tapered, as distinguished from the conventional form of collet in which the contact between collet and work piece is, under all conditions except a single special case, only a circumferential line contact.

Another object is collet construction and means for operation embodied in a propelling pencil.

Still other objects and advantages .will be apparent to those skilled in the art upon reference to the following description and the accompanying drawings in which Fig. 1 is a central longitudinal sectional view of a propelling pencil embodying the collet and means for operation thereof as well as lead propulsion means.

Fig. 2 is a perspective view of a detail.

Fig. 3 is a view on line 3-3 of Fig. 2.

Fig. 4 is a central longitudinal sectional view of a file handle embodying the collet.

Figure 5 is a perspective view of a detail of the latter.

Figure 6 is a section on line 66 of Figure 5.

Figure 7 is a section on line |l of Figure 1.

In the drawings, the collet or gripping means is shown by itself in Figures 2, 3, 5 and 6, these being functionally of the same form but having certain differences of form as will be noted. They consist of elongated members I0 and I I0, having axial passages H and l I, the passage being shown as cylindrical and the passage I being rectangular and tapered (seeFigure 4) Themembers ||l--| ID are slotted from both ends as shown at |2-|| 2 with the slots except one extending each to near the opposite end of the member. In each form of the collet one of the slots |2A-| |2A is out through from end to end. Further, these members Ill-Ill) are each provided with beveled or frustroconical end portions as at '|3| l3.

Referring now to Figure 1, showing a pencil, the collet I0 is shown as having the rod of lead 20 extending through it, the collet being mounted within the tapered end 2|A of an outer tube 2|, the inner wall of which is so shaped as to fit one of the beveled ends of member Ill. The other beveled end of member I0 is engaged by the collar 22A fixed into the end of aninner tube 22, the latter fitting within tube 2|.

The tube 2| is somewhat longer than tube 22 and is interiorly threaded as at 23 to receive the correspondingly threaded end of a sleeve 220, the projecting end of which is of a diameter substantialy equal to the O. D. of tube 2|. The inner end of sleeve 22C contacts a ring 22B which in turn abuts the rear end of tube 22 so that relative rotation of tube 2| and sleeve 22C to screw the latter inwardly will move tube 22 toward the collet I0 and cause the collet to be contracted.

In the expanded or relaxed condition of collet I0, the lead may be moved manually, but means is also shown for mechanically propelling the lead outward.

This propelling means consists of a third tube 30 rotatably mounted within tube 22 and sleeve 22C and extending to substantially the mid-portion of the assembly, being provided with an enlarged end 30A which may be integral or consist of a separate sleeve fixed in place as by pin 303. A recess in the enlarged end of tube 30 serves to hold an eraser 3|. I

The inner end of tube 30 carries a nut 32 fixed therein as by pin 32A while within the tube 22, a short distance beyond the end of tube 30 is slidably mounted an axially bored block 33 fixed against turnin in tube 22 by a pin 33A. This pin extends through the axial bore and through the screw shaft 34. As shown, the tube 22 is slotted as at 22D to receive that portion of pin 33A projecting from block 33, thus preventing rotation of the block While permitting it to move lengthwise of the tube. Further, the extreme end of pin 33A enters a suitable longitudinal slot or spline 2IB in the inner wall of tube 2| and thus maintains the tube 22 and block 33 from rotation in tube 2|.

The shaft 34, threaded to cooperate with the nut 32, is moved longitudinally through relative rotation of tubes 22 and 33 and abuts the end of the lead 20.

In operating the lead 20, it is first released by relative rotation of tube 2| and sleeve 220, then propelled outward the desired distance by relative rotation of tubes 22 and 30. The tubes 2| and 22 are then again operated to lock the lead in its new position.

In Figures 4, 5 and 6 is shown an adaptation of the collect as a holder for a file. In these figures, the collect H0 is shown as used with a metal handle H5, this being provided with an axial countersunk bore 8 at the inner end portion of which is an angular portion 16A adapted to fit and coact with one beveled end of collet H0. The countersink HEB is threaded to receive a corresponding sleeve H1 having its axial passage of such size as to accommodate the collet I III and provided at its outer end with a beveled portion H'IA adapted to fit and coact with the other beveled end of collet H0. Sleeve H1 is also shown as provided with sockets 1B in its end face to coact with a suitable wrench for sleeve rotation.

The collet i B is of course contracted or relaxed by the endwise movement of sleeve H1.

Now having described the invention and the preferred embodiment thereof, it is to be underby the scope of the claims which follows: I claim:'

ends with the slots from one end alternating with and overlapping for the greater portion of their length the slots from the other end, and having one of said slotsextending through from one end to the other and a structure surrounding said member and provided with female conical surfaces adapted to coact with the conical surfaces on said member to contract or relax said slotted gripping member when said female conical surfaces are moved toward or away from each other, and means in said structure for so moving said surfaces.

2. In a device of the character described a handle provided with an axial bore open to one end thereof for receiving an article to be held, said bore being counterbored and said counterbore terminating in a conical or beveled portion,

stood that said invention is to be limited, not 7 to the specific details herein set forth, but only 1. A collet comprising a gripping 'member having a cylindrical longitudinal bore andconi cal at its end portions and slotted from both,

a sleeve surrounding the counterbored end of said handle and having an oppositely arranged beveled inner end coaxial with the first, a collet having an axial cylindrical passage for reception of said article and beveled end portions adapted to coact with the bevels in said sleeve and counterbore and held therebetween, means for moving said sleeve and handle relatively whereby to force the first mentioned bevels over the beveled ends of said collet, said collet-being provided with a plurality of radial slots, each extending from one end to near the other end and alternate slots opening to alternate ends, said slots overlapping for the greater portion of their length and one of said slots extending from one end to the other, whereby to permit the collet to contract and grip the articleextending through said collet throughout the length of the latter.

HENRY D. FOWLIE.

REFERENCES ('JITEDv The following references arepf recoid in. the fileof this patent:

UNITED STAT-ES PATENTS Number Name, Date 160,954 Reittey- Mar. 16, 1875 696,745 OBrien' Apr. 1,1902 991,668 Taylor May 9, 1911 1,482,369 Kruschitzki Jan. 29 1924 2,265,238 Koehler Dec. 9,1941 2,321,028 Johnson June 8-, 194=3 OTHER REFERENCES- CurtisiAmerican Mach), July .2 1, 1921,,vol, 55, No. 3, pg. 111.. 

